What standby power really costs you in an EV charger
Updated · Reviewed against the current ChargerAtlas dataset
Short answer: across all 380 certified chargers, standby draw runs from effectively zero to 14.6 W. At a typical $0.17/kWh, the median unit (3.5 W) costs about $5.26 a year doing nothing, and even the worst costs under $22. Standby is a tiebreaker between otherwise equal chargers — not a reason to pick a slower one.
What standby power is
A wall charger is energized 24/7. Between charging sessions its electronics — control board, pilot signaling, and on networked units the Wi-Fi radio — keep drawing a few watts. The EPA measures this as "no vehicle mode" input power during certification, which is why we can compare every certified unit on equal terms instead of quoting marketing numbers.
The math
A watt of continuous draw is 8.76 kWh per year (1 W × 8,760 h ÷ 1,000). At the U.S. average residential rate of about $0.17/kWh:
| Standby draw | Energy per year | Cost per year |
|---|---|---|
| 1 W | 8.8 kWh | $1.49 |
| 3.5 W (median certified charger) | 30.9 kWh | $5.26 |
| 14.6 W (highest in the dataset) | 127.6 kWh | $21.69 |
Your rate scales the cost linearly: at California-style $0.30/kWh, multiply by ~1.8. Note that certification is doing real work here — the whole point of the ENERGY STAR EVSE program is capping idle losses, and uncertified chargers aren't measured at all.
Best and worst in the current dataset
| Lowest standby | W | $/yr |
|---|---|---|
| Lite-On Technology Corp Charging Station | 0.10 | $0.15 |
| Tesla Mobile Connector | 0.43 | $0.64 |
| Schumacher SEV1670 | 0.69 | $1.03 |
| TOPBAND TB-AC240US | 0.72 | $1.07 |
| Pando Electric Pando 001 Smart Outlet | 0.75 | $1.12 |
| Highest standby | W | $/yr |
|---|---|---|
| ChargePoint CP6000 (ChargePoint-CP6000 Single Port) | 14.56 | $21.69 |
| Blink Network, LLC Series 8 | 11.70 | $17.42 |
| Elinta Charge, UAB CityCharge V2 | 11.58 | $17.24 |
| RENOVA R-EVC/A48S | 11.02 | $16.41 |
| HBE-AC32A02ST-U | 10.91 | $16.25 |
A handful of units report 0 W — typically portable cord sets that power down completely when unplugged from the vehicle. Tables regenerate automatically when the dataset refreshes.
How much should this weigh in your decision?
Keep it in perspective: the spread between the median and the worst certified charger is roughly $16.43 a year — less than a single fast-food lunch, and about 3% of a typical EV's ~$500–600 annual home-charging bill. Standby draw is worth checking when two candidates are otherwise tied (it's listed on every ChargerAtlas spec page), and networked units predictably idle a little higher — quantified in the smart-charger guide. It should never outrank amperage fit (match the car), installation type, or cable quality.